Walnut: Health Benefits & Nutrition Facts

Walnuts are edible kernels obtained from tree belonging to the Juglandaceae
family, in the genus, Juglan. The nuts are enriched
with many health-benefiting nutrients, especially Omega-3 fatty acids that
are essential for optimum health.

Juglan
species plants are medium sized, semi-tropical, deciduous trees
believed to be originating in the mountain ranges of Central Asian or
southern Europe region.

There exist at least 30 different cultivars types of walnut. The three popular verities grown for their commercial purpose
are the English or
Persian walnut (Juglans regia), the Black walnut
(Juglans nigra), and the White
or butternut walnut (Juglans cinerea). Commercially, the
nuts are being cultivated in the United States of America, Romania,
France, Turkey, and China. After plantation, the tree takes
approximately four years until it produces its first major crop.

During each season, walnut fruits are ready for
harvesting by August, when their thick green hull begins to crack open to
expose light brown, hard-shelled “walnut” inside. Each nut features
roughly spherical in shape, about the size of a medium-sized lemon, weighing about 10-15 g, and
enclosing single (bi-lobed) edible kernel inside. Structurally, the walnut kernel consists of two
uneven, corrugated lobes, off white in color and covered by a papery
thin, light brown layer. The lobes are partially attached to each
other. Oil extracted from the nuts, apart from cooking,
has also been used
as base or carrier oil in medicine, and in aromatherapy.

Health
benefits of Walnuts

Walnuts are rich source
of energy and contain health benefiting nutrients, minerals,
antioxidants and vitamins that are essential for optimum health.

They are rich in monounsaturated fatty acids
(about 72%) like oleic acid and an excellent source of all important omega-3 essential fatty acids like
linoleic acid, alpha-linolenic acid (ALA) and arachidonic acids.
Regular intake of walnuts in the diet help in lowering total as well as
LDL or “bad cholesterol” and increases HDL or “good cholesterol” levels
in the blood. Research studies suggest that Mediterranean diet which is
rich in mono-unsaturated fatty acids, and omega-3 fatty acids help to
prevent coronary artery disease, and strokes by favoring healthy blood
lipid profile.

Eating as just as 25 g of walnuts per day provides
about 90% of RDI (recommended daily intake) of omega-3 fatty acids.
Research studies have suggested that n-3 fatty acids by their virtue of
anti-inflammatory action help lower blood pressure,
cut down coronary artery disease, and stroke risk, and offer protection from breast, colon and prostate cancers.

Additionally, they are rich source
of many phyto-chemical substances that may contribute to their overall
anti-oxidant activity, including melatonin, ellagic acid,
vitamin E, carotenoids, and poly-phenolic compounds. These
compounds known to have potential health effects against cancer, aging,
inflammation, and neurological diseases.

Scientists at University of Scranton,
Pennsylvania had recently discovered that walnuts have highest levels
of popyphenolic antioxidants than any other common edible nuts. 100 g
of these nuts carry 13541
µmol TE (Trolex equivalents) of oxidant radical absorbance
capacity (ORAC). Eating as few as six to seven walnuts a day could help scavenge almost all the disease causing free radicals from
the human body.

Further, they are an excellent source of vitamin E,
especially rich in gamma-tocopherol; carry about 21 g per 100 g
(about 140% of daily-required levels). Vitamin E is a powerful lipid
soluble antioxidant, required for maintaining the integrity of cell
membrane of mucus membranes and skin by protecting it from harmful
oxygen-free radicals.

They are also packed
with many
important B-complex groups of vitamins such as riboflavin, niacin,
thiamin, pantothenic acid, vitamin B-6, and folates.

They also very are rich
source of minerals such as manganese,
copper, potassium, calcium, iron,
magnesium, zinc, and selenium. Copper is a cofactor for many vital
enzymes, including cytochrome c-oxidase and superoxide dismutase (other
minerals function as co-factors for this enzyme are manganese and
zinc). Zinc is a co-factor in many enzymes that regulate growth and
development, sperm generation, digestion, and nucleic acid synthesis.
Selenium is an important micronutrient, which functions as a co-factor
for anti-oxidant enzymes such as glutathione peroxidases.

Walnut oil has flavorful nutty aroma and
exhibits
excellent astringent properties. Applied locally, it helps to keep skin
well protected from dryness. It has also been used in cooking, and as
“carrier or base oil” in traditional medicines in massage therapy,
aromatherapy, in pharmaceutical and cosmetic industry.

Safety
profile

Walnut allergy
is a type of hypersensitivity reaction to food
substances prepared by the use these nuts. It is due to prior sensitization
of the immune system by allergens in the nuts, which may lead to severe
physical symptoms like pain abdomen, vomiting, swelling of lips and
throat leading to breathing difficulty, and chest congestion.
Therefore, it is advised to avoid any food preparations that contain
these nut products in known case of walnut allergic individuals.